On 26/03/2019 10:00, Paolo Bonzini wrote:
> On 21/03/19 13:46, Laurent Vivier wrote:
>> +
>> +ifneq ($(CONFIG_USER_ONLY),y)
>> #######################################################################
>> # authz-obj-y is code used by both qemu system emulation and qemu-img
>>
>> @@ -21,21 +27,11 @@ block-obj-$(CONFIG_REPLICATION) += replication.o
>>
>> block-obj-m = block/
>
> Two remarks:
>
> 1) Isn't CONFIG_USER_ONLY set to y even if tools are built?
Yes, you right. I didn't test combination "--enable-user --enable-tools
--disable-system"
>
> 2) Notwithstanding the answer to (1), why is this part needed at all?
> The only things that have dependencies on crypto-obj-y, io-obj-y etc.
> are $(SOFTMMU_SUBDIR_RULES), the tools, and the tests that you are
> disabling already. Therefore, why are they built at all for user-only
> builds?
The change was based on the comments in the file.
And for the crypto part we need it and this could explain:
commit fb37726db77b21f3731b90693d2c93ade1777528
Author: Daniel P. Berrange <berra...@redhat.com>
Date: Wed Sep 2 10:57:27 2015 +0100
crypto: move crypto objects out of libqemuutil.la
Future patches will be adding more crypto related APIs which
rely on QOM infrastructure. This creates a problem, because
QOM relies on library constructors to register objects. When
you have a file in a static .a library though which is only
referenced by a constructor the linker is dumb and will drop
that file when linking to the final executable :-( The only
workaround for this is to link the .a library to the executable
using the -Wl,--whole-archive flag, but this creates its own
set of problems because QEMU is relying on lazy linking for
libqemuutil.a. Using --whole-archive majorly increases the
size of final executables as they now contain a bunch of
object code they don't actually use.
The least bad option is to thus not include the crypto objects
in libqemuutil.la, and instead define a crypto-obj-y variable
that is referenced directly by all the executables that need
this code (tools + softmmu, but not qemu-ga). We avoid pulling
entire of crypto-obj-y into the userspace emulators as that
would force them to link to gnutls too, which is not required.
> 3) I don't really see the need or advantage in conditionalizing tests of
> libqemuutil.a, which is built even for linux-user builds (even though
> e.g. the coroutines code does not end up in the binary). Since most of
> the tests you are removing are related to the block layer, perhaps you
> can add
>
> CONFIG_BLOCK := $(call lor, $(CONFIG_SOFTMMU), $(call notempty,$(TOOLS))
>
> and use it to conditionalize the testcases that depend on block-obj-y?
>
I agree.
Thanks,
Laurent
